Processing Steps, Continued

Compute the Specific Loudness from the excitation pattern for each frame

• Includes a compressive nonlinearity depending on the frequency and level of the excitation pattern

• Specific loudness can be interpreted as loudness per ERB (i.e., loudness versus critical band)

If desired, Instantaneous Loudness = sum of the specific loudness over frequency at any time

Short- and Long-Term Loudness = nonlinearly lowpass-filtered (across time) instantaneous loudness

The Loudness Spectrogram is defined as either raw Specific Loudness (instantaneous), or some filtering of it across time (short-term or long-term loudness vs. frequency)